Stifel Nicolaus' Stephen Willey said in an earlier note Viropharma will likely need to show more dose-ranging data on the product's effectiveness. While the analyst noted 2,000-unit sub-Q data validates utilization of rHuPH20 usage with Cinryze, he warned logistical issues may pop up related to manufacturing capacity and cost before a twice-per-week dosing could be a feasible option. Willey also suggested the data confirms an unformulated sub-Q1 C1 inhibitor would not be a viable treatment option.

Despite the cautious comments, Stifel Nicolaus and Willey maintain a Buy rating and $42 price target on shares of Viropharma.

Visit our Analyst Ratings page to track all the market-moving analyst action on shares of Viropharma.